1962 Lark lower pinion race

[Cadillac-ack-ack]

I asked about this a couple of threads ago but may have been lost because of multi questions at the time.

With the upper gearcase assembly upside down, the lower pinion bearing race (the one with the 20 loose rollers) gets driven in towards the three piece thrust washer. As I recall, there was, and has to be a space/clearance between the bearing race and the top (it's upside down) thrust washer. How much is good? Both the Seloc and the factory manual simply say to install it. Obviously to me that driving it in until it bottomed out as you would most bearings would solidly lock the three piece thrust washer up solid causing the pinion's shoulder to grind away on the washer. - Pete

 

[racerone]

Are you 100 % sure it would lock up the thrust bearing ?

 

[Cadillac-ack-ack]

Are you 100 % sure it would lock up the thrust bearing ?

Yes, I can not see how it would not. One flat thrust washer goes in first and lays on the machined surface. The flat caged needle bearing goes in next fallowed by the other flat washer. These three pieces all float nicely but if the lower pinion bearing race is then driven home tight against the last washer you would be left with a locked up assembly that will not spin. In this scenario the pinion's top end would be bearing on a thrust washer that would not turn and just grind it. - Pete

 

[F_R]

It would seem to me that there is a step in the bore, preventing the roller bearing race from going that deep. But I haven't looked at one in many years, so could be mistaken.

You are aware that the two flat thrust washers are not identical, right?

 

[Cadillac-ack-ack]

It would seem to me that there is a step in the bore, preventing the roller bearing race from going that deep. But I haven't looked at one in many years, so could be mistaken.

You are aware that the two flat thrust washers are not identical, right?

A step in the bore would be logical but there is not one. I am aware of the difference and correct washer placement. It is the center hole that is of different diameters. The OD is the same. With the three pieces making up the thrust washer assembly installed, there is a shiny clean area just above the outside most washer about 1/16" wide, I feel that marks the depth the pinion bearing race should driven to. I've looked and looked for alternatives but see none. Just seems strange to me that the Seloc manual, even with it's limitations is loaded with "cautions". Seems that not driving that race totaly home would be in there. - Pete

 

[Cadillac-ack-ack]

For the life of me I can't see how not "some" space between the pinion bearing race and the thrust washer would allow the system to work so I'm settling on 1/32" - 1/16". I think anything will work so long as the race is driven far enough in so what is protruding will not be more than the machined bore in the gearcase itself. I'll have to do some calculating. - Pete

 

[Joe Reeves]

To refresh my memory after an absence in the trade since 1991, I looked through the manual. It states...."Press against the lettered side of bearing and install flush with step at top of recess. Bottoming bearing in recess may distort bearing cage."

 

[Cadillac-ack-ack]

To refresh my memory after an absence in the trade since 1991, I looked through the manual. It states...."Press against the lettered side of bearing and install flush with step at top of recess. Bottoming bearing in recess may distort bearing cage."

Thank's Joe. I read similar words in one of my factory manuals but it was talking about the UPPER driveshaft bearing, the one located just under the waterpump. The lower pinion bearing (20 loose rollers) is the one in question. It does not help that the Seloc manual keeps calling the LOWER pinion bearing the UPPER pinion bearing. It also does not help that this manual mostly references a V4 Electromatic lower unit that has the thrust washers IN the gearcase itself and not in the housing above it. Very different than the 40HP. - Pete

 

[Cadillac-ack-ack]

For the life of me I can't see how not "some" space between the pinion bearing race and the thrust washer would allow the system to work so I'm settling on 1/32" - 1/16". I think anything will work so long as the race is driven far enough in so what is protruding will not be more than the machined bore in the gearcase itself. I'll have to do some calculating. - Pete

This is exactly what I ended up doing. Made up a couple of spacers that my drift bottomed out on leaving exactly 3/64" clearance to the lower thrust washer. When I turn the drive shaft I can feel the pinion engaging forward and reverse gears tooth to tooth with a kind of notchy-ness. It was like this before and I believe it to be normal considering the very slow speed I'm able to turn it by hand. I feel that at idle speed as the pinion meshes with the drive gears it will ride up a bit and actually then come in contact with the thrust washer smoothing the whole gear box out. Also there is only assembly oil in the gearcase at present. Does this sound about right? - Pete

 

[F_R]

When running under load, the thrust forces on the gear teeth make them move apart from one-another, as you suggested.

 

[Joe Reeves]

Apparently, as "ack-ack" mentioned, my previous post/reply #7 pertained to the "upper" bearing under the water pump (confusing manual... my bad).

Pertaining to installing that large lower pinion bearing... it always states using a special tool to have it installed.

I checked various service manuals just to see if the wording might change to include an alternative method ie installing it by eye. Strange to find that it does not.

 

[Cadillac-ack-ack]

Thank's F_R, I am sure it's put together correctly and it's very smooth through the prop shaft. Happy about the confirmation.

Hi Joe, I'm sure you have access to more manuals than me. I'm working from a Selocs and a factory one provided b jimmbo. I'm thinking it's possible this '62 (model # 35933L), being, I believe, the first of the Selectric Shifts, may have a one off arrangement with this bearing. The pictures in the manuals look right but the references to "pressing from the lettered side of the bearing" make no sense as this pinion bearings outer race has no letter'd side. It is the same top and bottom, the 20 bearing rollers are loose and located between two internal snap-rings when loaded into the race. It looks more like the style used in the earlier manual gearcase. Parts reference pictures of what is SUPPOSED in there looks like the style of caged needle bearing that does have a stouter lettered side and a plane side. Very confusing but thankfully the original roller bearing style used in my motor had all good parts. - Pete

 

[racerone]

That bearing with loose rollers is shown to be used from 62 to the last year of production 1970.-----A very good set up it is !!--

 

[Cadillac-ack-ack]

That bearing with loose rollers is shown to be used from 62 to the last year of production 1970.-----A very good set up it is !!--

Seems to be true. Considering the bronze flecks found throughout that were all flattened nicely by those rollers, and without any damage whatsoever (race and each roller inspected with magnifying glass)....